1. Field of the Invention
This invention relates generally to warp knitting machines, and more particularly, to a weft inserting apparatus for use on warp knitting machines.
2. Description of the Prior Art
The prior art abounds with many different types of weft inserting devices that are known to those of ordinary skill in the knitting machine art. Several of these are discussed in U.S. Pat. No. 3,916,649 to Karl Kohl. However, these include the following disadvantages: If the spools are required to be in motion, and there is weft breakage or the like, the complete weft inserting mechanism must be stopped; the threads must pass through long lever guides which cause undesirable friction forces and may tend to tear the threads; a "FIG. 8" feed mechanism causes undesirable thread abrasion if the path of the thread from the spool to the thread guide is not straight and direct; or a magazine type of arrangement which changes the warp threads from a tensioning chain to a magazine, and in turn, transfers the warp threads to the needle bed to be entrapped by the ground threads of the warp knitting machine includes additional driving mechanisms and chains increasing the chances of breakdown.
Thus, the prior art includes the embodiment wherein the weft thread is extended the entire length of the machine by an angle thread transmission means which obtains the successive threads from a weft thread provider disposed on one side of the warp knitting machine. Prior art machines of this type also utilize weft thread magazines, which are adapted to receive the weft threads from the angle thread provider that provides the weft threads one after another, parallel to the needle bed of the machine, and then in turn, presents the weft threads to the needle bed at each predetermined stitch as desired.
In most cases, the prior art magazines include an arrangement having transport chains provided perpendicular to the needle bed disposed on both sides of the machine. The magazine was generally on the rearward side of the needle bar. Since the guide bars had to be driven from both sides of the machine and the magazine driving mechanism which was required to have a transport driving means located on both sides of the machine also, had to be contained within the available space. With limited space it was impossible to build magazines of very great width, or if relatively large widths were utilized, it was necessary to reduce the number of weft threads that were available for insertion. Also, since the weft threads must pass through an additional mechanism such as a magazine requires, additional means to maintain thread cleanliness and means must be provided to prevent the loss of tension as the threads travel in a thread-tensioning device.